Aircraft construction



Oct. 25, 1958*.-

H] G. KLEMM Er AL AIRCRAFT consr'nuc'rxon Filed D60. '7, 1937 2 Sheets-Sheet 1 INVENTOR. HERMAN G.KL.MM BERTHOU D C.BOUL.T0

ATTORNEY.

'Oct. 25, 1938. H. s. KLEMM EI AL AIRCRAFT CONSTRUCTION Filed Dec. 7, 1937 2 Sheets-Shut 2 v INVENTOR.

HERMAN G.KL.ENM BERTHOUD C.BOULTQN ATTORNEY.

Patented Oct. 25,1938- to be supplied to the ,the'scope of the appended claims.

, :UNITED- STATES amcasr'r CONSTRUCTION Herman G. Klemm, Baltimore, and Berthond G. Boulton, Towson,.Md., assignors to The Glen -L..Martin Company, Baltimore, Md.

Claims. (01. 244-53) This invention relates to an aircraft construction and is a division of our co-pending applicaiiigzhi, Serial Number 118,072, filed December 29, One object of this invention is to provide novel means for supplying air to the intake of an engine carburetor at predetermined temperatures.

Another object of this invention is to provide novel' means for preheating air to be supplied to the intake of an engine carburetor.

A further object is to provide novel means for regulating and controlling the temperature of V intake of an engine carburetor."

The above and other'objects will be made apparent throughout the further description ofthe invention when taken in connection with the actinctly understood that the drawings are not a definition of the invention; but illustrate certain forms by means of which the invention may be eifectuated. The invention will be defined by In thedrawings: Figure 1 1s afragmentary plan view of an aircraft" of the bi-motor'ed monoplane type illustrat- 'in'g one embodiment of the invention,

Figure 2 is a sectional view taken line 2-2 of Figure 1,"

Figure 3 is an enlarged detail view embodying theinvention, I I

Figure 4 is an enlarged detail sectional view similar to Figure 2 illustrating another embodi ment of the invention, Figure 5 is a fragmentary top plan view of Figure 4, p

Figure 6 is an enlarged sectional view taken along the line 6-6 of Figure 4', and Figure 7 is a diagrammatic view of a control arrangement embodying the invention.

The present invention is illustrated and dealong the scribed in connection with an aircraft of the bimotored monoplane type. However, it is to be understood that the invention isequally adaptable for use with other types of aircraft.

Referring to the drawings, Figures 1, 2, and 3 illustrate one embodiment of the invention where intake l5. In the form shown, the engine I3 is of the radial typeand mounted within a ring cowling IS, the rear edge of which is adapted to cooperate with the forward portion of a nacelle body l1 and defining an annular opening Hi therebetween. The ring cowling i6 is provided withthe usual opening IS in the front thereof for supplying cooling air to the cooling 'system of the power plant.

The exhaust means i4 here employed comprises an exhaust ring 2|, the latter being operably connected with the exhaust of each of the radially disposed engine cylinders by means of pipes 22. Extending rearwardly of the exhaust ring is an exhaustpipe 23 which may be a continuation of the exhaust ring 2i and is employed for connecting the exhaust ring 2| with an exhaust silencer represented in its entirety by 24.

The exhaust silencer 24 is located within a comthat the entire compartment may be bodily against any egress of gases into that portion of the wing body forward of the compartment 25.

Novel means is provided for cooling the compartment 25 which consists of the provision of a compartment surrounding the compartment 25. This compartment 55 is supplied with cooling air by way of an air duct 56 connecting an opening '51 disposed in the forward portion of the wing ii.

The air passing through the air duct 56 and into the compartment 55 is expelled in the fairing region of the wingthrough openings 58. This compartment 55 serves to cool the compartment 25 as well as to provide an air insulating means between .the compartment 25 and the adjacent I surfaces of the aircraft. The compartment 55 may be further provided with an asbestos inresented in its entirety by I, and a carburetor forated or slotted top 26' is preferably constructed g *removed from theaircraft. This is important in that the compartmentis adapted for readily cleaning; inspecting, repairing, and replacing.

The entrance of the pipe 23 is preferably provided with suitable means such as shownat 28 'for'sealing the interior of the compartment 25 sulation as shown at 21. The air duct may be provided with suitable valve control means, not

shown, for regulating the amount of air entering the opening 51 in the forward portion of the wing II for controlling the cooling of the compartment 25 as well' as maintaining the drag through the'air duct 56 and compartment 55' at a minimum.

take of the carburetor when such heated air is desired. This is accomplished by providing a manifold like covering or housing 3| for at least a portion of the length of the exhaust pipe 23 and thereby defining an air passageway 33 connecting the interior of the engine cowling IS with the air passageway or opening 32 positioned within the fairing region of the wing II. This particular region being at a point where the aerodynamic pressure is negative eifects a suction by way of the opening 32 from the housing 3| and operates to draw air from the cooling system supplied through the opening l9, enginecowling l5, into the forward end of the housing 3| as indicated by the arrow 33, through the housing 3| andoperating to absorb heat from the exhaust pipe 23. At some selected point in the housing 3| there is provided an air duct 34 conecting the interior of the housing 3| with an air scoop 35, the latter being provided with suitable controls 35 which may be operated either by the pilot, or by automatic means, for scooping up air and inducing it into the housing 3| and directing it in the direction indicated by the arrow 33'.

In order to effectively accomplish this opera.- tion, the opening 32 is provided with suitable means such as shown at 31 (see Figure 2) for closing the opening 32 and eliminating any suction therethrough, also a suitable connection.

a such as an air duct, 38 is provided for connecting the forward end or the interior of the housing 3| with the intake of the carburetor l5. Any suitable means may be employed for connecting or disconnecting the intake of the carburetor l with the air duct 35. Therefore, it follows that when the opening 32 is closed that the scoop 35 will direct air through the air duct 34 forwardly through the housing 3|, through the air duct 33.

and into the intake II at the engine carburetor and that during the passage of'air through the exhaust housing 3| it will absorb heat from the exhaust pipe 23 to suiiiciently heat the air to a temperature desired at the carburetor.

- The carburetor intake I5 is provided with novel means for selectively receiving either air from cthr:t housing 3| or from the exterior of the air- In the form shown, the intake of the carburetor I5 is connected with the exterior of the aircraft by means of an air duct 53 and the interior of the housing 3| by means of an air duct 33. Suitable valves 5i and 52 are located within the air ducts 53 and 33 respectively adjacent the intake of the carburetor II for selectively connecting the intake of the carburetor with either a supply of cold air or hot air. when it is desired to supply hot air to the intake of the carburetor l5, it is desirable to close the opening 32 by the means 31 .and open the air scoop "as well as close the entrance of the cooling air into the forward end of the housing 3|. Figure 7 illustrates a control systemwhereby a single actuating handle 53 may be employed for simultaneously operating the valves 5| and 52, scoop 35, means 31, and a valve 54 posi'ilOllBd within and adapted to close the mouth or forward end of the housing 3|. As illustrated in Figures 2 and 7 the several controls are in the osition for supplying heated air to the intake of the carburetor i5, the scoop 35 being open while the opening 32 in the fairing region of the wing l l is closed as well as the forward end of the housing 3| by the valve 54. This permits air to pass by way of the scoop 35, through the air duct 34, through housing 3|, air duct 35, and into the intake of the carburetor I5. It will be noted that if the actuating handle 53 is moved to the left as viewed in Figure '7 that the several control connections will be operated to simultaneously close and open the valves 52 and 5| respectively and also simultaneously close the scoop 35 and open the opening 32 and valve 54 within the mouth of the forward end of the housing 3|.

Figures 4 and 5 illustrate another embodiment of the invention wherein the compartment 25 is located in the fairing region of nacelle H. The exhaust pipe 23in this embodiment, while shorter than that described above, is also supplied with a housing 3| communicating with the interior of an annularly shaped housing 33 disposed about the exhaust ring 2|. Thefairing of the nacelle i1 is also provided with opening 32 connecting the interior of the housing 3| with the exterior of the nacelle surface. The cooling air for the exhaust pipe 23 is supplied through tube like connections 4| surrounding exhaust pipes 22 and connecting the interior of the housing 33 with the interior of the engine cowling l5. Cooling air enters the tube like members 4| .as indicated by the arrows 42 (see Figure 4) passes into the housing 33, and out through the opening 32 by way of the housing 3|.

This embodiment includes an improved-muiiier or silencer for expanding and reducing the velocity and temperature of the exhaust gases. In each of the silencers 24 (see Figure 6) the exhaust gases initially enter an inner cylinder 44, the latter having perforations on its upper surface as shown at 45 for permitting the gases to pass into a second cylinder 45, this cylinder having perforations on its lower surface as shown at 41 for permitting the gases to pass into the compartment 25 for further expansion and reduction of velocity and temperature. These gases are subsequently freed to pass out through the perforated or slotted top 25 of the compartment 25. Any number of cylinders may be employed. However, it is desired that therespective openings such as 45 and 4l be pcaitioncd on opposite sides of the adjacent cylinders in order that the gases will be directed around the cylinders prior to entering the surrounding cylinders or compartment 25.

While I have illustrated and described this inappended claims.

We claim: 1. In an aircraft having an airfoil, an engine,

a carburetor attached to said engine,and a cowlin'g surrounding said engine, an exhaust gas and carburetor air intake system comprising an exhaust conduit, a first means to convey air from adjacent said engine in heat dissipating exchange with said conduit to an exhaust port in an area of negative pressure on a surface of said airfoil, a second means including a portion of said first means for conveying air in heat exchange relation with said conduit to said carburetor, and means for rendering operative either of said first or second means while simultaneously rendering the other-of said means inoperative.

2. In an aircraft having an airfoil, an engine, and a cowling surrounding said engine,a carburetor air intake and engine gas exhaust system comprising a first manifold means for supplying air under positive pressure from a surface of said cowling, second manifold means for conducting exhaust gases' from said engine to an exhaust port, casing means surrounding said second manifold for conveying air from an area of positive air pressure adjacent said engine to a second exhaust port located in an area of negative pres sure on the surface of said airfoil, conduit means connecting said casing means with said first conduit means, air scoop means connected to said 6 casing means, and valve means for the simultaneous closing of said conduit means, scoop means,

\and second exhaust port while opening said first 

